Prior to serving on the Supreme Court he was the three term governor of California where he showed his credentials as a Rockefeller Republican by instituting New Deal-esque programs in the state, making him an incredibly popular governor. This led to him being selected as the vice presidential candidate for the GOP in 1948 running alongside Thomas Dewey, another liberal Republican. Despite the ticket being expected to win it did not.

In 1963 Warren was the chairman of The President's commission on the Assassination of President Kennedy (The Warren Commission), which was established to investigate the assassination of President John F. Kennedy. The commission concluded that Lee Harvey Oswald killed Kennedy, which is clearly wrong.